As is generally known, in a hybrid vehicle, a clutch, which is disposed between a motor generator and an engine, is engaged during start of the engine for starting the engine by a motive power from the motor generator (see Patent document 1).
In the above prior art, an engine, a first clutch, a motor generator, and a second clutch are arranged in series with each other in that order from the side of a driving power source to the side of drive road wheels in a power-train system.
When an engine start request is made, the motor generator (the motor) is torque-controlled, and the first clutch is brought into engagement, while slipping the second clutch, thereby increasing revolution speeds of the motor so as to start the engine. At this time, fully taking account of gear rattling, which may occur from a coast state, engagement of the first clutch starts after a preset stand-by time, measured from the engine start request, has expired.